This invention relates to a method for preparing particulate saccharides and, more particularly, to a method for preparing particulate saccharides containing two or more saccharides that can be crystallized only with difficulty.
A method of preparing particulate saccharides is known in which a solution containing saccharides is concentrated and cooled, whereupon the formed saccharide crystals are separated and dried. The process, however, is limited to saccharides that can be crystallized easily, such as glucose or sucrose.
On the other hand, those saccharides that are difficult to crystallize industrially are handled in the form of a highly concentrated solution. However, it is costly to transport saccharides in the form of solutions. Further, saccharides in the form of solutions cannot be used for powdered foods, thus restricting the use of such materials.
It is known to dry two or more saccharides which are difficult to crystallize, such as saccharides containing oligosaccharides or honey, by spray drying, vacuum freeze drying and vacuum drying methods.
When spray drying a solution of saccharides of high concentration and high viscosity that can be crystallized difficultly, it is necessary to lower the concentration of the solution of the saccharides to be sprayed by, for example, adding water to the solution. It is also necessary to add excipiens, such as dextrin, to the solution, so that much heat is needed in drying. The produced powdered saccharides are also not satisfactory in that they are low in purity while being low in sweetness and poor in flavor.
In vacuum freeze drying a solution of saccharides of high concentration and high viscosity that can be crystallized difficultly, it also is necessary to lower the concentration of the solution of saccharides, in a manner similar to the above described spray drying. This fact plus the required freezing and warming, creates economic disadvantages.
On the other hand, the vacuum drying method has a drawback that, although it is possible to use a solution containing the saccharides as a starting material in high concentration and in high density, the produced saccharides are low in bulk density. To overcome this drawback, a method of granulating the particulate saccharides by dry agglomeration has been proposed. However, in this dry agglomeration, problems are presented in that the solubility of the produced saccharides is lowered.